1. Field of the Invention
The present invention relates to a component having a lubricating surface formed therein in a compressor.
2. Description of the Related Art
A swash plate type compressor has pistons which reciprocatingly move upon rotation of a swash plate which rotates with a rotating shaft, as disclosed in the Japanese Unexamined Patent Publication No.59-231181, No.8-199327, No.9-209926 and No.10-153169. Shoes are disposed between the front end surface of the swash plate and the piston and between the back end surface of the swash plate and the piston, so that a rotational force of the swash plate is transferred to the pistons via the shoes. The shoes are made of an iron based material and make slide contact with the rotating swash plate, so the slide contact portion between the shoe and the swash plate may possibly abrade or sticking may occur between the shoe and the swash plate. For this reason, it is required to improve the slide contact characteristic of the swash plate to the shoes.
In the art disclosed in the above described respective publication and the Japanese Unexamined Patent Publication No.10-8230, a lubricating surface formed of a copper based material which mainly contains copper is provided on the slide contact portion of the swash plate. Such lubricating surface improves the slide contact characteristic of the swash plate to the shoes.
In order to further improve the sliding property of the swash plate to the shoes, the copper based material contains lead having a low melting point, in the arts disclosed in the Japanese Unexamined Patent Publication No.59-231181 and No.10-153169. The lead contained in the copper based material is softened due to the high temperature caused by the friction between the swash plate and the shoes, and the softened lead appears on the slide contact surfaces between the swash plate and the shoes to increase lubricity of the slide contact surface. In case of the swash plate disclosed in the Japanese Unexamined Patent Publication No.10-8230, a small amount of lead exist as impurities.
However, it is not preferable to use lead which would cause lead poisoning, and it is required to restrict the amount of lead to be used.
It is an object of the present invention to provide a component of a compressor, which includes a lubricating surface portion in a slide contact area, and in which a good slide contact characteristic may be obtained while using no lead.
In order to achieve the above object, the present invention provides a component of a compressor, the component including a lubricating surface portion in a slide contact area, the lubricating surface portion being formed of a copper based or aluminum based material which does not contain lead but contains solid lubricant other than lead.
The solid lubricant contained in the copper based or aluminum based material improves the slide contact characteristic of the lubricating surface portion when it is exposed to the lubricating surface. Since the solid lubricant other than lead is contained in the copper based or aluminum based material which does not contain lead, the use of lead is avoided.
Preferably, a lubricating film made of a copper based or aluminum based material containing a solid lubricant is provided in the slide contact area to form said lubricating surface portion.
In this case, preferably, the lubricating film is made on a base material by sintering.
The surface of the lubricating film made of the copper based or aluminum based material becomes the lubricating surface.
Preferably, the compressor comprises a swash plate type compressor having a swash plate rotatable with a rotating shaft, a piston, and a shoe disposed between the swash plate and the piston so as to make slide contact with the swash plate and the piston, whereby a rotational motion of the swash plate is transferred to the piston via the shoe to reciprocatingly move the piston, and said component is the swash plate, in which the swash plate has a lubricating surface and the shoe has a lubricating surface to make slide contact with the lubricating surface of the swash plate.
The slide contact area of the swash plate, which makes slide contact with the shoe, is suitable for the area where a lubricating surface is formed.